Browse Prior Art Database

Means for Building a Star Coupler Within a Fused Fiber Plate

IP.com Disclosure Number: IPCOM000100425D
Original Publication Date: 1990-Apr-01
Included in the Prior Art Database: 2005-Mar-15
Document File: 3 page(s) / 98K

Publishing Venue

IBM

Related People

Bregman, MF: AUTHOR [+4]

Abstract

This article describes how to build a high-density optical star coupler by using technology developed for fused fiber plates. An optical star coupler is a device that mixes optical energy coming into ports so that each of N output ports carries 1/Nth of the energy of each of N input ports. However, the technology of optical star couplers is based on fusing fibers or on planar wave-guide technology, which inherently limits the number of inputs and the uniformity of the mixed signal. (See U.S. Patent 4,715,027 and references therein.) There are also excess losses due to scattering and other imperfections.

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Means for Building a Star Coupler Within a Fused Fiber Plate

       This article describes how to build a high-density
optical star coupler by using technology developed for fused fiber
plates.  An optical star coupler is a device that mixes optical
energy coming into ports so that each of N output ports carries 1/Nth
of the energy of each of N input ports. However, the technology of
optical star couplers is based on fusing fibers or on planar
wave-guide technology, which inherently limits the number of inputs
and the uniformity of the mixed signal.  (See U.S. Patent 4,715,027
and references therein.)  There are also excess losses due to
scattering and other imperfections.

      The idea described here demonstrates how to build such a
coupler by taking advantage of the manufacturing process of fiber
plates.  By removing interstitial extramural absorber in regions of
the plates, it is possible to couple optical signals between fibers
under careful control, and thereby potentially produce a very
high-density coupling with a superior quality of mixed signal.

      Fused fiber plates consist of an assembly of small glass fibers
melted together in a continuous array.  These plates usually consist
of step index fibers with interstitial absorber, called extramural
absorber (EMA), fused in the regions between the individual fibers.
The role of the step index and the EMA are to image the light in
the direction of the fibers while preventing optical crosstalk due to
scattered light or fiber-to-fiber coupling in the direction
transverse to t...